Oxydehydrogenation process for alkylaromatics and catalyst therefor

ABSTRACT

This invention relates to an improved process for the dehydrogenation of alkyl-substituted aromatic compounds to the corresponding alkenyl-substituted aromatics in the presence of oxygen and in the presence of an improved metal phosphate catalyst composition.

This is a division of application Ser No. 792,637, filed May 2, 1977.

BACKGROUND OF THE INVENTION

Current commercial dehydrogenation practices as for example in theconversion of ethyl benzene to styrene, suffer from the disadvantages oflow conversions, while higher conversion oxydehydrogenations suffer frompoor selectivities. Selectivity is especially important in thisparticular reaction since the starting materials for producing styrenecomprise over 80 percent of its manufacturing costs. Thus there is acontinuing search for catalytic materials that are more efficient inminimizing side reactions and improving conversion rates.

A number of catalysts and catalytic systems have been disclosedutilizing various phosphates and pyrophosphates for the conversion ofalkyl aromatics to derivatives having side-chain unsaturation. Forexample U.S. Pat. No. 3,923,916 claims nickel pyrophosphate as asuperior catalyst for the oxydehydrogenation of alkyl aromatics. U.S.Pat. No. 3,933,932 and U.S. Pat. No. 3,957,897 disclose the use oflanthanum, rare earth and alkaline earth phosphates, respectively, asoxydehydrogenation catalysts for alkyl aromatics. However catalystcompositions containing arsenic, antimony, bismuth or cadmium phosphateswhich have demonstrated outstanding activity for the dehydrogenationreaction of the present invention have heretofore not been disclosed.Although U.S. Pat. No. 3,873,633 utilizes acobalt-bismuth-phosphorus-oxygen composition as a catalyst for theoxydehydrogenation of paraffinic hydrocarbons to monoolefins ordiolefins, the use of this type of catalyst for the conversion of alkylaromatics to unsaturated side-chain derivatives has heretofore not beenknown.

SUMMARY OF THE INVENTION

The present invention comprises the process for the oxydehydrogenationof alkyl-substituted aromatic compounds to the correspondingalkenyl-substituted aromatics and the novel catalyst compositionstherefor. More specifically the invention comprises theoxydehydrogenation of alkyl aromatic compounds to form the correspondingunsaturated side-chain derivative wherein the alkyl aromatic contains atleast one alkyl group having from two to six carbon atoms, and whereinthe alkyl group is attached to only one aromatic ring. The aromatic maybe a mononuclear or a condensed-ring dinuclear aromatic, or acorresponding nitrogen-containing heterocyclic aromatic.

The process comprises passing a gaseous mixture of molecular oxygen suchas air and the alkyl aromatic compound in the presence or absence of adiluent such as steam, carbon dioxide, nitrogen, or an inerthydrocarbon, over a catalyst at a temperature of from about 300° toabout 650° C., said catalyst having a composition represented by theempirical formula:

    A.sub.a M.sub.b M.sup.1.sub.c M.sup.11.sub.d B.sub.e P.sub.y O.sub.x

wherein

A is an alkali metal and or thallium;

M is one or more of the elements of nickel, cobalt, copper, manganese,magnesium, zinc, calcium, niobium tantalum, strontium or barium;

M¹ is one or more of the elements of iron, chromium, uranium, thorium,vanadium, titanium, lanthanum or the other rare earths;

M¹¹ is one or more of the elements of tin, boron, lead, germanium,aluminum, tungsten or molybdenum;

B is bismuth, tellurium, arsenic, antimony, cadmium, or combinationsthereof;

P is phosphorus; and

wherein a through y have the following values:

a=0 to 20;

b=0 to 20;

c=0 to 20;

d=0 to 4;

e=0.1 to 20;

y=8 to 16;

x=the number of oxygens required to satisfy the valence requirements ofthe other elements present; and

wherein the sum of b+c+e is greater than 1.

Preferred in this invention are catalyst compositions wherein

a=0 to 2;

b=4 to 12;

c=0.2 to 4;

d=0 to 2;

e=0.5 to 5; and

y10 to 14.

Contemplated within the scope of the present invention are the catalystcompositions represented by the empirical formula:

    A.sub.a M.sub.b M.sup.1.sub.c M.sup.11.sub.d B.sub.e P.sub.y O.sub.x

wherein A, M, M¹, M¹¹ B & P have the same compositions as has beenhereinbefore designated, and wherein a through y have the followingvalues;

a=0 to 5;

b=4 to 20;

c=0.1 to 10;

d=0 to 4;

e=0.1 to 12;

y=8 to 16;

x=the number of oxygens required to satisfy the valence requirements ofthe other elements present; and

wherein the sum of 2b+3(c+e) is greater than 9 and less than 3y.

Preferred is the composition wherein:

a is in the range of 0-1;

b is in the range of 4 to 12;

c is in the range of 0.1 to 4;

d is in the range of 0 to 2;

e is in the range of 0.1 to 4; and the sum of 2b+3(c+e) is greater than9 and less than 3y.

The catalysts of this invention are unexpectedly good oxydehydrogenationcatalysts. For example in the dehydrogenation of ethyl-benzene tostyrene, per pass conversions to styrene in the range of 70% andselectivities of up to 90% are obtained.

The catalysts useful in the instant process may be used alone orsupported on a carrier. Suitable carrier materials include silica,Alundum, titania and mullite and particularly phosphate-type carrierssuch as zirconium phosphate, antimony phosphate, aluminum phosphate andespecially boron phosphate. In general, the support may be employed inamounts less than 95% by weight of the final catalyst composition, andthe catalyst may be incorporated in the carrier by coating, impregnationand coprecipitation.

These catalysts may be prepared by coprecipitation or by other methodsknown in the art. Generally they are prepared by mixing an aqueoussolution of the metal nitrates with an aqueous solution of ammoniumdihydrogen phosphate and drying this precipitate.

The catalyst may be calcined to produce desirable physical propertiessuch as attrition resistance, optimum surface area and particle size. Itis generally preferred that the calcined catalyst be furtherheat-treated in the presence of oxygen at a temperature of above 250° C.but below a temperature deleterious to the catalyst.

Among the alkyl aromatics contemplated to be within the scope of theinvention are the mono-substituted aromatics such as, for example, ethylbenzene, isopropyl benzene, secondary-butyl benzene; disubstitutedaromatics such as ethyl toluene, diethyl benzene, t-butyl ethyl benzene;trisubstituted aromatics such as the ethyl xylenes; condensed ringaromatics such as ethyl naphthalene, methyl ethyl naphthalene, diethylnaphthalene; and nitrogen-containing heterocyclic aromatics such asethyl pyridine, methyl ethyl pyridine, ethyl quinoline, ethylisoquinoline, and the like. Particularly preferred reactants in thisreaction are ethyl benzene which is readily converted to styrene,diethyl benzene which is converted to mixtures of ethyl styrene anddivinyl benzene, ethyl pyridine and methyl ethyl pyridine which areconverted to vinyl pyridine and methyl vinyl pyridine, respectively.

The reaction may be conducted in a fixed-bed or a fluidized-bed reactorat temperatures as low as 300° C., although optimum temperatures for thedehydrogenation of the alkyl side-chains are in the range of from about400° to 600° C., and there is no apparent advantage in operating attemperatures much in excess of 650° C.

The pressure at which the instant process is usually conducted is aboutatmospheric, although pressure of from slightly below atmospheric up toand above 3 atmospheres are operable.

The apparent contact time employed in the instant process may be withinthe range of 0.1 to 50 seconds, and for good selectivity and yields acontact time of from 1 to 15 seconds is preferred.

The molar ratio of oxygen to alkyl aromatic compound fed to the reactorcan range from about 0.5 to about 4 moles of oxygen per mole of alkylaromatic compound, but a preferred range is from about 0.5 to about 1.5moles of oxygen per mole of aromatic compound. The oxygen employed maybe in the form of pure oxygen, although the use of air is preferred forpurposes of convenience.

Diluents such as steam, carbon dioxide, nitrogen, inert hydrocarbons orother inert gases may also be used and amount of from 0 to 20 volumes ofdiluent per volume of alkyl aromatic compound are suitable.

The following examples serve to illustrate the feasibility and theimprovement obtained in the oxydehydrogenation process utilizingcatalysts of the present invention as compared with catalysts of theprior art.

SPECIFIC EMBODIMENTS

Examples 1-26 are representative of the present invention andComparative Examples A-E are representative of prior art processes.

CATALYST PREPARATIONS Comparative Example A Ni₂ P₂ O₇

Nickel nitrate hexahydrate (168.5 g) was dissolved in 500 cc of water,and acidity was adjusted to a pH of 6.4 with ammonia. Ammoniumdihydrogen phosphate (77.7 g) was dissolved in 250 cc of water, and thepH adjusted to 6.8 with ammonia. The solutions were mixed and stirred atroom temperature for 15 minutes, after adjusting the pH to 6.0 withammonia, then filtered. The light green precipitate was filtered, driedat 110° C. and heat-treated for 3 hours at 290° C., 3 hours at 427° C.,and 2 hours at 550° C. to give a tan solid having a surface area at 14m² /g.

Comparative Example B-Mg₂ P₂ O₇

Magnesium nitrate hexahydrate (309.2 g) was dissolved in 60 cc of waterwith heating. Ammonium dihydrogen phosphate (138.2 g) was dissolved in100 cc of water with heating. The solutions were mixed and stirred withheating until a white thick paste formed. The paste was dried at 110°C., heat-treated at 290° C. for 3 hours, 427° C. for 3 hours, and 550°C. for 16 hours in air to give a white solid having a surface area of21.8 m² /g.

Comparative Example C-La₄ (P₂ O₇)₃

Lanthanum nitrate hexahydrate (Trona code 548) (130 g) was dissolved in31.5 cc nitric acid and diluted to 250 cc with water. Ammoniumdihydrogen phosphate (57.1 g) was dissolved in 250 cc of water andacidified to a pH of ˜1 with 25 cc nitric acid. On mixing the solutionswith stirring, an opalescence formed. After stirring 22 hours withheating a milky white precipitate formed. On heating to boiling, the gelthickened. The gel was filtered, dried at 110° C., heat-treated at 290°C. (3 hours), 427° C. (3 hours) and 550° C. (16 hours) in air to give awhite solid having a surface area of 17 m² /g.

Comparative Example D-Co₇ Fe₃ P₁₂ O₄₁.5

Ferric nitrate nonahydrate (121.2 g) and cobalt nitrate hexahydrate(203.8 g) were dissolved in 10 ml. of water with heating. Ammoniumdihydrogen phosphate (138.0 g) was dissolved in 100 ml of water withheating. The solutions were mixed and stirred with heating until a thickpaste formed. The paste was dried at 110° C., then heat-treated at 290°C. (3 hours), 427° C. (3 hours) and 550° C. (3 hours) in air to give ablue solid with a surface area of 0.8 m² /g.

Comparative Example E-Co₂ P₂ O₇

Cobalt nitrate hexahydrate (349.1 g) was dissolved in 20 cc of waterwith heating. Ammonium dihydrogen phosphate (138.0 g) was dissolved in100 cc of water with heating. The solutions were mixed and stirred withheating until a thick purple paste formed. The paste was dried at 110°C., and heat-treated at 290° C. (3 hours), 427° C. (3 hours) and 550° C.(16 hours) to give a blue solid with a surface area of 12.2 m² /g.

EXAMPLE 1 Bi₈ P₁₂ O₄₂

Bismuth nitrate pentahydrate (194 g), 5 cc nitric acid (conc.) and 45 ccof water were warmed to 75° C. with stirring. Ammonium dihydrogenphosphate (69.0 g) was added to 50 cc of water and warmed to 75° C. Thetwo solutions were mixed, then stirred and heated until a white pasteformed. The paste was dried at 110° C., heat-treated at 290° C. (5hours), 427° C. (3 hours), and 550° C. (3 hours) in air. A white solidresulted with a surface area of 0.3 m² g.

EXAMPLE 2 25% Bi₈ P₁₂ O₄₂ -75%BPO₄

Bismuth nitrate pentahydrate (19.4 g) was dissolved in 1 cc of nitricacid (conc.) and 9 cc of water, with heating. Ammonium dihydrogenphosphate (6.9 g) was dissolved in 25 cc of water. The solutions werecombined, and 40.4 g boron phosphate were added. The boron phosphatepowder (-200 mesh) was made by mixing 121 g of 85% H₃ PO₄ with 62 g H₃BO₃, warming to 40° C. for 5 hours, drying the resulting paste at 110°C. and calcining in air at 300° C. (8 hours). After the BPO₄ -additionthe paste was dried at 110° C. and heat-treated as in Example 1. A whitesolid having a surface area of 17 m² /g resulted.

EXAMPLE 3 5%-Cu₁.5 BiP₅ O₁₅.5 -95% BPO₄

A Boron phosphate powder was made from 45 g H₃ BO₃ and 50 cc 85% H₃ PO₄by refluxing H₃ BO₃ in Eastman sec-butanol (350 cc) distilling off 170cc alcohol-water azeotrope, then adding H₃ PO₄. After furtherdistillation to remove water, the resultant gel was dried and calcinedat 260° C. Cupric nitrate hexahydrate (1.60 g) and bismuth nitratepentahydrate (1.75 g) were dissolved in 2.5 cc of nitric acid and 22.3cc of water, and added to 25 g BPO₄ powder. The paste was dried at 110°C. and heat-treated as in Example 1. The resultant light blue solid hada surface area of 63 m² /g.

EXAMPLE 4 Fe₁₀ Bi₀.7 P₁₂ O₄₆

Ammonium dihydrogen phosphate (138 g) was dissolved in 100 cc of waterwith heating. Ferric nitrate nonahydrate (404 g) and bismuth nitratepentahydrate (35.1 g) were added, in order, to 10 cc of water andheated. The resultant nitrate solution was added to the phosphatesolution. A slurry formed which was heated with stirring to removewater, then dried and calcined as in Example 1. The light tan solidobtained had a surface area of 3.8 m² /g.

EXAMPLE 5 Co₁₀ Bi₀.7 P₁₂ O₄₁

Ammonium dihydrogen phosphate (138 g), cobalt nitrate hexahydrate (291.1g) and bismuth nitrate pentahydrate (35.1 g) were dissolved and combinedas in Example 4. After heat-treatment as in Example 1, by the resultingblue solid had a surface area of 5.4 m² /g.

EXAMPLE 6 co₇ Fe₃ Bi₀.7 P₁₂ O₄₃

A nitrate solution was made up of cobalt nitrate hexahydrate (203.8 g),ferric nitrate nonahydrate (121.2 g) and bismuth nitrate pentahydrate(35.1 g) with 10 cc of water, and added to an ammonium dihydrogenphosphate (138.0 g) solution as in Example 4. After heat-treatment as inExample 1, the resulting blue solid had a surface of 7.7 m² /g.

EXAMPLE 7 50%Co₇ Fe₃ Bi₁ P₁₂ O₄₃ -50%BPO₄

A nitrate solution was made up of cobalt nitrate hexahydrate (85 g),ferric nitrate nonahydrate (50.5 g) and bismuth nitrate pentahydrate(20.2 g) with 5 cc water. It was added to an ammonium dihydrogenphosphate solution (57.5 g) in 100 cc of water to which 53 g boronphosphate prepared as in Example 2, was added. After stirring andheating, the slurry was dried anc calcined as in Example 1. Theresulting blue solid had a surface area of 11.9 m² /g.

EXAMPLE 8 Co₉.5 Fe₀.5 Bip₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (276.5 g),ferric nitrate nonahydrate (20.2 g) and bismuth nitrate pentahydrate(48.5 g). It was added to a solution of ammonium dihydrogen phosphate(138 g) in 100 cc of water, dried and heat-treated as in Example 1. Theresulting blue solid had a surface area of 12.6 m² /g.

EXAMPLE 9 Mg₉ FeBiP₁₂ O₄₂

A nitrate solution was made up of magnesium nitrate hexahydrate (115.4g), ferric nitrate nonahydrate (20.2 g) and bismuth nitrate pentahydrate(24.3 g). It was added to a solution of ammonium dihydrogen phosphate(69 g) in 50 cc water, dried and heat-treated as in Example 1. Theresulting cream colored solid had a surface area of 12.0 m² /g.

EXAMPLE 10 Co₉ CrBiP₁₂ O₄₂

A nitrate solution was made up of the cobalt nitrate hexahydrate (131g), chromium (III) nitrate nonahydrate (20 g), bismuth nitratepentahydrate (24.3 g) and 5 cc of water. It was added to a solution ofammonium dihydrogen phosphate (69 g) in 50 cc of water, dried andheat-treated as in Example 1. The resulting blue solid had a surfacearea of 14.3 m² /g.

EXAMPLE 11 Co₇ La₁.5 Bi₂ P₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (101.9 g),ianthanum nitrate hexahydrate (32.8 g), bismuth nitrate pentahydrate(48.5 g) and 7 cc of concentrated nitric acid. It was added to asolution of ammonium dihydrogen phosphate (69 g) in 50 cc of water,dried and heat-treated as in Example 1, except that 550° C. heat-treatedwas extended to 16 hours. The resultant blue solid had a surface area of19.4 m² /g.

EXAMPLE 12 Co₈ La₀.5 Bi₂ P₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (116.4 g),lanthanum nitrate hexahydrate (10.9 g), bismuth nitrate pentahydrate(48.5 g), and 3 cc of concentrated nitric acid with 10 cc water. It wasadded to ammonium dihydrogen phosphate (69 g) dissolved in 50 cc water,then dried and heat-treated as in Example 11. The resulting blue solidhad a surface area of 7.7 m² /g.

EXAMPLE 13 Co₉ La₁.0 Bi₁ P₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (131 g),lanthanum nitrate hexahydrate (217. g) and bismuth nitrate pentahydrate(24.3 g) with 10 cc of water. It was added to ammonium dihydrogenphosphate (69 g) dissolved in 50 cc of water. The slurry was dried andheat-treated as in Example 1. The resulting blue solid had a surfacearea of 10.5 m² /g.

EXAMPLE 14 K₀.01 Co₉ La₁ BiP₁₂ O₄₂

A nitrate solution was prepared as in Example 13. A 10 cc solution ofpotassium acetate (0.5 g/100 cc) was added to the mixed nitrates, andthe nitrate solution was added to an ammonium dihydrogen phosphatesolution as in Example 13. The slurry was dried and heat-treated as inExample 11. The resultant blue solid had a surface area of 19.0 m² /g.

EXAMPLE 15 Co₇ Zn₂ La₁ BiP₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (101.9 g),zinc nitrate hexahydrate (29.8 g), lanthanum nitrate hexahydrate (21.7g) and bismuth nitrate pentahydrate (24.3 g) in 5 cc of water. It wasadded to an ammonium dihydrogen phosphate (69 g) solution in 50 cc ofwater. After stirring and heating, the slurry was dried and heat-treatedas in Example 11. The resultant blue solid had a surface area of 8.6 m²/g.

EXAMPLE 16 Co₉ CeBiP₁₃ O₄₅

Ceric ammonium nitrate (27.4 g) was dissolved in 5 cc nitric acid(concentrated) and 100 cc of water. Bismuth nitrate pentahydrate (24.3g) and cobalt nitrate hexahydrate (131 g) were added to the cericsolution and dissolved. The resultant solution was added to an ammoniumdihydrogen phosphate (74.8 g) solution in 50 cc of water. The resultantslurry was dried and heat-treated as in Example 1. The solid that formedhad a surface area of 10.3 m² /g.

EXAMPLE 17 Mg₉ La₁ BiP₁₂ O₄₂

A nitrate solution was made up of magnesium nitrate hexahydrate (115.4g), lanthanum nitrate hexahydrate (21.7 g) and bismuth nitratepentahydrate (24.3 g) in 10 cc of water. It was added to an ammoniumdihydrogen phosphate (69 g) solution in 50 cc of water. After stirringand heating, the slurry was dried and heat-teated as in Example 1. Theresultant white solid had a surface area of 27 m² /g.

EXAMPLE 18 Co₉ "Di₁ "BiP₁₂ O₄₂

"Didymium" oxide, mixed rare earths (16.5 g) (Trona Corp. Code 422) wasdissolved in 25 cc of concentrated nitric acid. Bismuth nitratepentahydrate (24.3 g) was added to the "didymium" solution which wasthen added to a solution of ammonium dihydrogen phosphate (69 g) in 50cc of water. A cobalt nitrate hexahydrate (131 g) solution in 10 cc ofwater was then added. The slurry was dried and heat-treated as inExample 1. The resultant blue solid had a surface area of 15.4 m² /g.

EXAMPLE 19 Co₉ Fe₁ TeP₁₂ O₄₂.5

Tellurium dioxide (8.0 g) was dissolved in 10 cc of nitric acid withwarming. This solution was added to a nitrate solution consiting ofcobalt nitrate hexahydrate (131 g) and ferric nitrate nonahydrate (20.2g) and 5 cc of water. The nitrate solution was added to an ammoniumdihydrogen phosphate (69 g) solution in 50 cc of water. The slurry wasdried at 110° C. and heat-treated as in Example 1, with the final 550°C. stage being performed in the stainless steel reactor. The resultantblue solid had a surface area of 59.9 m² /g.

EXAMPLE 20 Co₁₀ Sb₁ P₁₂ O₄₁.5

A slurry of Sb₂ O₃ (14.6 g) in 10 cc glacial acetic acid and 10 cc waterwas added to a solution of ammonium dihydrogen phosphate (69.0 g) in 50cc of water. A solution of cobalt nitrate hexahydrate (145.5 g) in 10 ccof water was added. After heating and stirring, the slurry was dried andheat-treated as in Example 1.

EXAMPLE 21 Co₁₀ As₁ P₁₂ O₄₁.5

A slurry of 9.9 g As₂ O₃ in 10 cc glacial acetic acid and 40 cc waterwas added to an ammonium dihydrogen phosphate solution (69.0 g in 50 ccof water). The remainder of the preparation was the same as in Example20.

EXAMPLE 22 Co₁₀ Cd₂ P₁₂ O_(x)

Cobalt nitrate hexahydrate (145.5 g) and cadmium nitrate tetrahydrate(30.8 g) were dissolved in 10 cc of water. This solution was added to anammonium dihydrogen phosphate solution (69 g) in 80 cc water. Theresultant slurry was dried and heat-treated as in Example 1.

EXAMPLE 23 Co₈ BaFeBiP₁₂ O₄₂

A nitrate solution was made up of cobalt nitrate hexahydrate (116.4 g),bismuth nitrate pentahydrate (24.3 g), ferric nitrate nonahydrate (20.2g) and 50 cc of water. Barium hydroxide octahydrate (15.8 g) wasacidified with 10% solution of concentrated nitric acid in water to a pHof 1.5, then added to the nitrate. The resultant slurry was added to anammonium dihydrogen phosphate solution (69 g) in 50 cc of water. Theslurry was dried and heat-treated as in Example 1, to give a solid witha surface area of 10.6 m² /g.

EXAMPLE 24 Co₉ CeBiP₁₂ O₄₅

The same catalyst as Example 16 was regenerated by passing air over thecatalyst at reaction temperature.

EXAMPLE 25 Mg₉ LaBiP₁₂ O₄₂

Same catalyst as Example 17 was regenerated by passing air over thecatalyst at reaction temperature.

EXAMPLE 26 K₀.1 Co₉ Cr₁ Bi₁ P₁₂ O₄₂

This catalyst was prepared in the same manner as the catalyst of Example10 except for the addition of potassium acetate (0.49 g) to the nitratesolution. The surface area was 15.2 m² /g.

The number of oxygen atoms in the catalysts in Examples 1 to 26 wereestimated. However, the number of oxygens may actually vary from about30 to 60, depending upon the reaction conditions.

The above catalyst compositions were employed in the oxydehydrogenationof ethyl benzene to styrene, diethyl benzene to divinyl benzene andmethyl ethyl pyridine to methyl vinyl pyridine in a fixed-bed reactorcomprising a 1/2-inch O.D. stainless steel tube having a catalyst volumecapacity of 15 cc.

A reactant mixture of air, aromatic compound and nitrogen were pre-mixedand fed to the reactor in a molar ratio of 5/1/2, respectively. Thereactor was maintained at a temperature of 530°-532° C. and atatmospheric pressure. The liquid hourly space velocity of the aromaticfeed over the catalyst was 0.23 hours⁻¹, and the contact time was 3.3seconds. Particle size of the catalyst employed was 20-35 mesh. Thepercent per pass conversion to the desired alkenyl aromatic compound andthe selectivity of the reactions reported in Tables 1 to 3 werecalculated in the following manner: ##EQU1##

                                      TABLE I                                     __________________________________________________________________________    OXYDEHYDROGENATION OF ETHYL BENZENE                                           TO STYRENE                                                                                                     Mole % Per Pass                                                                        Mole %                                                     Mole % Conversion                                                                       Yield    Selectivity                         Example No.                                                                          Catalyst        of Ethyl Benzene                                                                        To Styrene                                                                             To Styrene                          __________________________________________________________________________    Comp. A                                                                              Ni.sub.2 P.sub.2 O.sub.7                                                                      55        43       79                                  Comp. B                                                                              Mg.sub.2 P.sub.2 O.sub.7                                                                      71        61       86                                  Comp. C                                                                              La.sub.4 (P.sub.2 O.sub.7).sub.3                                                              55        41       75                                  Comp. D                                                                              Co.sub.7 Fe.sub.3 P.sub.12 O.sub.41.5                                                         27        24       88                                  Comp. E                                                                              Co.sub.2 P.sub.2 O.sub.7                                                                      47        37       78                                   1     Bi.sub.8 P.sub.12 O.sub.42                                                                    14        12.5     85                                   2     25%Bi.sub.8 P.sub.12 O.sub.42 -75%BPO.sub.4                                                   68        59       86                                   3     5%Cu.sub.1.5 BiP.sub.5 O.sub.15.5 -95%BPO.sub.4                                               51        42       82                                   4     Fe.sub.10 Bi.sub.0.7 P.sub.12 O.sub.46                                                        39        18       72                                   5     Co.sub.10 Bi.sub.0.7 P.sub.12 O.sub.41                                                        55        48       86                                   6     Co.sub.7 Fe.sub.3 Bi.sub.0.7 P.sub.12 O.sub.42.5                                              59        50       85                                   7     50%Co.sub.7 Fe.sub.3 Bi.sub.1 P.sub.12 O.sub.43 -50%BPO.sub.4                                 62        53       85                                   8     Co.sub.9.5 Fe.sub.0.5 BiP.sub.12 O.sub.42                                                     75        64       87                                   9     Mg.sub.9 Fe.sub.1 BiP.sub.12 O.sub.42                                                         65        55       84                                  10     Co.sub.9 CrBiP.sub.12 O.sub.42                                                                74        65       89                                  11     Co.sub.7 La.sub.1.5 Bi.sub.2 P.sub.12 O.sub.42                                                75        65       87                                  12     Co.sub.8 La.sub.0.5 Bi.sub.2 P.sub.12 O.sub.42                                                69        60       87                                  13     Co.sub.9 LaBiP.sub.12 O.sub.42                                                                79        71       90                                  14     K.sub.0.01 Co.sub.9 La.sub.1 BiP.sub.12 O.sub.42                                              78        70       90                                  15     Co.sub.7 Zn.sub.2 La.sub.1 BiP.sub.12 O.sub.42                                                73        66       90                                  16     Co.sub.9 CeBiP.sub.13 O.sub.45                                                                77        69       90                                  17     Mg.sub.9 La.sub.1 BiP.sub.12 O.sub.42                                                         78        70       90                                  18     Co.sub.9 "Di".sub.1 BiP.sub.12 O.sub.42                                                       63        51       82                                  19     Co.sub.9 Fe.sub.1 TeP.sub.12 O.sub.42.5                                                       60        50       83                                  20     Co.sub.10 Sb.sub.1 P.sub.12 O.sub.41.5                                                        58        46       80                                  21     Co.sub.10 As.sub.1 P.sub.12 O.sub.41.5                                                        52        43       83                                  22     Co.sub.10 Cd.sub.2 P.sub.12 O.sub.42                                                          49        42       87                                  __________________________________________________________________________

                  TABLE II                                                        ______________________________________                                        OXYDEHYDROGENATION OF METHYL ETHYL PYRIDINE                                   TO METHYL VINYL PYRIDINE                                                                           Mole                                                                          %                Mole                                                         Con-     Mole    %                                                            ver-     %       Selec-                                                       sion of  Yield of                                                                              tivity to                                                    (Me Et   (Me     (Me                                     Example              Py-      Vinyl   Vinyl                                   No.    Catalyst      ridine)  Pyridine)                                                                             Pyridine)                               ______________________________________                                        23     Co.sub.8 BaFeBiP.sub.12 O.sub.42                                                            35       23      66                                      24     Co.sub.9 CeBiP.sub.13 O.sub.45                                                              32       21      66                                      25     Mg.sub.9 LaBiP.sub.12 O.sub.42                                                              40       26      65                                      ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        OXYDEHYDROGENATION OF DIETHYL BENZENE*                                        TO DIVINYL BENZENE                                                                                         Mole %  Mole %                                                                Yield of                                                                              Selectivity                                                 Mole %    Ethyl-  to Ethyl                                                    Conversion                                                                              Vinyl & Vinyl &                                  Ex.                of Diethyl                                                                              Divinyl Divinyl                                  No.  Catalyst      Benzene   Benzene Benzene                                  ______________________________________                                        26   K.sub.0.1 Co.sub.9 Cr.sub.1 BiP.sub.12 O.sub.42                                             78        40   19   76                                     ______________________________________                                         *(Eastman T 1Q31, M, P Mixture)                                          

We claim:
 1. The catalyst composition represented by the empiricalformula:

    A.sub.a M.sub.b M.sup.1.sub.c M.sup.11.sub.d B.sub.e P.sub.y O.sub.x

wherein A is an alkali metal and or thallium; M is one or more elementsof nickel, cobalt, copper, manganese, magnesium, zinc, calcium, niobium,tantalum, strontium or barium; M¹ is one or more of the elements ofiron, chromium, uranium, thorium, vanadium, titanium, lanthanum or theother rare earths; M¹¹ is one or more of the elements of tin, boron,lead, germanium, aluminum or tungsten, B is one or more of the elementsof bismuth, antimony, and arsenic; P is phosphorus; andwherein a throughy have the following values: a=0 to 5; b=4 to 20; c=0.1 to 10; d=0 to 4;e=0.1 to 12; y=8 to 16; x=the number of oxygens required to satisfy thevalence requirements of the other elements present; andwherein the sumof 2b+3(c+e) is greater than 9 and less than 3y.
 2. The catalystcomposition of claim 1 whereina is in the range of 0-1; b is in therange of 4 to 12; c is in the range of 0.1 to 4; d is in the range of 0to 2; e is in the range of 0.1 to 4; andthe sum of 2b+3(c+e) is greaterthan 9 and less than 3y.
 3. The catalyst composition of claim 1 whereinM in the catalyst composition is cobalt, M¹ is lanthanum, and B isbismuth.
 4. The catalyst composition of claim 1 wherein M in thecatalyst composition is cobalt, M¹ is iron and B is bismuth.
 5. Thecatalyst composition of claim 1 wherein M in the catalyst composition ismagnesium, M¹ is lanthanum and B is bismuth.
 6. The catalyst compositionof claim 1 wherein M is selected from the group consisting of magnesiumand cobalt.
 7. The catalyst composition of claim 1 wherein M' isselected from the group consisting of iron, chromium, uranium, thorium,titanium, lanthanum and rare earth element.
 8. The catalyst compositionof claim 7 wherein M' is selected from the group consisting of iron andlanthanum.
 9. The catalyst composition of claim 1 wherein the catalystcontains tin.
 10. The catalyst composition of claim 1 wherein thecatalyst contains bismuth and antimony.
 11. The catalyst composition ofclaim 1 wherein the catalyst contains bismuth.
 12. The catalystcomposition of claim 1 wherein the catalyst contains antimony.
 13. Thecatalyst composition of claim 1 wherein d is
 0. 14. The catalystcomposition of claim 1 wherein d is greater than 0.